Some of the above works extract information from user-generated tags [1]}, [2]}, [3]}, [4]}.
Instead we focus on content-based image information only, rather than the associated metadata. The term “content" in this context refers to information extracted from the image that relates to the objects and scene of the image.
In related work, image features extracted with VGG-16 [5]} are used to extract private information from images [6]}.
A combination of learned and hand-crafted features derived from convolutional layers is used in the Privacy-Convolutional Neural Network with Hierarchical features (PCNH) [7]} model. iPrivacy [8]} uses multi-task learning to identify sensitive objects in images by considering relationships between objects and their co-occurrences with defined privacy settings.
